Improvement in dental a regulators



J. B. MQPHERSON. Dental Articulator.

No. 223,157. Patented Dec. 30,1879.

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UNITED STATES PATENT OEEroE.

JAMES B. MGPHERSON, OF BALTIMORE, MARYLAND.

IMPROVEMENT IN DENTAL ARTICULATORS.

Specification forming part of Letters Patent No. 223,157, dated December30, 1879; application filed November 6, 1879.

To all whom it may concern:

Be itknown that I, JAMES B. IVICPHERSON, of the city of Baltimore andState of Maryland, have invented certain Improvements in DentalArticulators, of which the following is a specification; and I do herebydeclare that in the same is contained a full, clear, and exactdescription of my said invention,reterence being bad to the accompanyingdrawings, and to the letters of reference marked thereon.

The first part of my said invention has reference to certainimprovements in means for securing the models which represent the jawsof the patient to the model-holders, forming a part of the articulator;the object of this part of the said invention being to furnish suchclamping devices for securing the models as will not perforate the sameor interfere with the fitting of the teeth thereto, while at the sametime admitting of the models being easily adjusted to and removed fromthe holders, and to dispense with plaster as a fastening material.

The second part of my said invention has reference to certainimprovements in the construction of the articulator, as will hereinafterfully appear.

In the further description of my said invention which follows, referenceis made to the accompanying drawings, forming a part hereof, and inwhich Figure I is an exterior side view of my improved dentalarticulator and an upper-jaw model, which is secured thereto. Fig. II isan exterior view of the same from the reverse side thereof. Fig. III isa view of the under side of the device. Fig. IV illustrates a modifiedconstruction of the clamping device hereinbefore alluded to.

Similar letters of reference indicate similar parts in all the views.

In the said drawings, A is a block, to which the model'holders B B arehinged. The modelholders consist of open plates conforming somewhat tothe shape of the mouth, and they are provided with clamps for holdingthe models, one of which models is shown and represented by b.

The clamps, as preferably constructed, consist of one or more fixedsharpened projections,

jections by means of a screw and nut, c and f.

Another construction of the clamp is illustrated in Fig. IV, and in thisthe adjustment is effected mainly by dividing the model-holder into twoparts-a fixed and a movable oneand providing the said parts or sectionswith projections, which are brought in contact with the model andsecured thereat. This fastening of the model to its holder by means of aclamp instead of by plaster, as is usually done, obviates the danger ofbreaking the model in its removal from the holder, such breakage beingcaused bya too firm adhesion of the model to the plaster connecting itto the holder. It also ofi'ers a more cleanly method of securing themodel to the holder; and the addition of the clamps adds practicallynothing to the cost of the articulator.

O U are set-screws, which are used when it is necessary to preventmovement of either model-holder independently of the block A. D is anadjustable stop to limit the closing of the model-holders when the teethare being fitted to the plate.

I am aware that a patent was granted April 30, 1840, to J. Cameron fordental articulators, in which the model is held to its holder by meansof a T-head bolt, which passes entirely through the model, the samebeing slotted for the purpose and recessed to fit the bolt-head. Thismanner of securing the model is not, however, applicable to the wants ofdentists at the present time, when artificial teeth are held in themonth by means of suction-plates, as the plate could not be formed onthe model without being perforated, which would render it worthless.Even in cases where suction'plates are not used to secure the teeth theslotting or perforating of the model is objectionable, as the model isthereby weakened, and therefore liable to be broken either in theprocess of fitting the head of the bolt in the slot or in somesubsequent manipulation of the model.

In myinvention, as described, the fastening devices are situatedexteriorly of the model, and do not come in contact with the plate orteeth, as the same are fitted to the model.

In view of the above-named patent I do not claim, broadly,a fasteningdevice for securing the model to its holder; but

What I claim as my invention is- 1. In a dental articulator, themodel-holders thereof, provided with adjustable clamps or holdingdevices located in such position with reference to the saidmodel-holders as to clamp the models exteriorly of the parts thereof towhich the plate or teeth-base is applied, substantially as hereinspecified.

2. The block A and model-holders B B, in

combination with the adjustable stops D, substantially as and for thepurpose herein set forth.

3. The model-holder B, pror ided with the set-screws 0, whereby the saidmodeLholders may be secured to the block A, and independent movementot'same prevented, substantially as herein described.

JAMES B. MGPHERSON.

Witnesses:

HARRY V. ALBAUGH, JNo. T. MADDOX.

